<dependency>  
    <groupId>com.google.guava</groupId>  
    <artifactId>guava</artifactId>  
    <version>30.1-jre</version>  
</dependency>

public void limitTest(){  
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");  
  
//創(chuàng)建令牌桶，一秒一個(gè)，容量為1  
RateLimiter rateLimiter = RateLimiter.create(1);  
//獲取放令牌的速率  
System.out.println("放令牌的速率："+rateLimiter.getRate());  
for (int i=0;i<5;i++){  
//獲取令牌，會(huì)阻塞，返回等待的時(shí)間  
double acquire = rateLimiter.acquire();  
System.out.println("第"+i+" 個(gè)令牌獲取到的時(shí)間："+LocalDateTime.now().format(dtf)+"，等待時(shí)間："+acquire);  
}  
  
//是否會(huì)立即獲取到令牌  
boolean tryAcquire = rateLimiter.tryAcquire();  
}

public @interface Limit {  
// 資源主鍵  
String key() default "";  
//最多訪問次數(shù),代表請(qǐng)求總數(shù)量  
double permitsPerSeconds();  
// 時(shí)間：即timeout時(shí)間內(nèi),只允許有permitsPerSeconds個(gè)請(qǐng)求總數(shù)量訪問，超過的將被限制不能訪問  
long timeout();  
//時(shí)間類型，默認(rèn)秒
TimeUnit timeUnit() default TimeUnit.SECONDS;  
  
//提示信息  
String msg() default "系統(tǒng)繁忙,請(qǐng)稍后重試";  
}

@Aspect  
@Component  
public class LimitAop {  
  
private final Map<String, RateLimiter> limitMap = Maps.newConcurrentMap();  
  
private DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");  

@Around("@annotation(com.limit.Limit)")  
public Object around(ProceedingJoinPoint joinPoint) throws Throwable{  
    MethodSignature signature = (MethodSignature) joinPoint.getSignature();  
    Method method = signature.getMethod();  
    //拿limit的注解  
    Limit limit = method.getAnnotation(Limit.class);  
    if (limit != null) {  
        // key作用：不同的接口，不同的流量控制，相當(dāng)于每個(gè)接口有一個(gè)對(duì)應(yīng)的令牌桶  
        String key = limit.key();   
        RateLimiter rateLimiter;  
        //驗(yàn)證緩存是否有命中key  
        if (!limitMap.containsKey(key)) {  
            //創(chuàng)建令牌桶  
            rateLimiter = RateLimiter.create(limit.permitsPerSeconds());  
            limitMap.put(key, rateLimiter);  
            log.info("新建了令牌桶={},容量={}", key, limit.permitsPerSeconds());  
        }  
        rateLimiter = limitMap.get(key);  
        //拿一個(gè)令牌，拿不到會(huì)一直阻塞 
        double acquire = rateLimiter.acquire(1);  
        log.info("{},獲取令牌時(shí)間{}", key,LocalDateTime.now().format(dtf));  
        
        /*
        //是否能立即拿到令牌，不能則桶里沒有，還沒到一秒鐘，進(jìn)行限流
        boolean acquire = rateLimiter.tryAcquire();  
        if (!acquire) {  
        log.info("令牌桶={},獲取令牌失敗", key);  
        throw new RuntimeException(limit.msg());  
        }*/  
        
        }  
    return joinPoint.proceed();  
    }  
}

@GetMapping("/limitTest")  
@Limit(key = "limitTest",permitsPerSeconds = 1,timeout = 1,msg = "觸發(fā)接口限流，請(qǐng)重試")  
public void limitTest(){  
    //其它邏輯代碼  
    //這里打印調(diào)用該接口執(zhí)行的時(shí)間，以便觀察限流  
    DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");  
    System.out.println(LocalDateTime.now().format(dtf));  
}